الفهرس 
WirelessCommunicationChannelCharacteristicsOnly 14 pages are availabe for public view
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Abstract
Multiple Input Multiple Output - Orthogonal Frequency Division
Multiplexing (MIMO - OFDM) technology becomes a new promising
technique for future wireless communication systems.
The idea behind MIMO is that the signals on the multiple transmit
antennas at one end and multiple receive antennas at the other end are
combined in such a way that the quality or the capacity is improved.
On the other hand, OFDM divides the allowed channel bandwidth into
sub-channels with narrower bandwidth. OFDM provides also efficient
usage of spectrum due to orthogonal carriers, simple equalization and
easy implementation.
MIMO-OFDM system, like any wireless communication systems,
must know the channel at the receiver side to recover the transmitted
data again; this can be achieved by using a channel e timator.
This thesis demonstrates the main characteristics of any wireless
communication channels, different propagation models and various
statistical distributions for multipath channel.
OFDM basic are illustrated and MATLAB simulations have been
conducted to evaluate the performance of OFDM ystem with perfect
channel state information at the receiver side only.
The analysis and simulation of MIMO system with different Space
Time Block Code (STBC) techniques and Layered Space Time (LST)
coding are demonstrated. For space time block code, different
orthogonal design codes are presented and the performance of
Maximum Likelihood (ML) receiver is evaluated through simulation.
.. The layered space time codes involve many architecture for receivers
including Zero Forcing (ZF) Minimum Mean Square Error (MMSE)
and successive cancellation receiver like QR decomposition, VBLAST/ZF
and V-BLASTIMMSE.The analysis and simulation of MIMO-OFDM wireless
communication systems are demonstrated using different channel
estimators including Least Square (LS) and Maximum A Posteriori
(MAP) in multiplexing.
New algorithms for decoding of Alamouti coded OFDM system over
time varying channel are proposed by considering the channel is
changed over two successive time periods, over Alamouti symbol,
instead of assuming the channel is unchangeable (static) over Alamouti
symbol as stated in the literature.
The simulation is done for the new AJamouti coded OFDM decoding
algorithms with different channel estimators including Least Square
(LS) and Maximum A Posteriori (MAP) and prove superior to the
other decoding algorithms.
Key words: Multiple Input Multiple Output (MIMO), Orthogonal
Frequency Division Multiplexing (OFDM) , Space Time Block Code
(STBC), Layered Space Time (LST), Zero Forcing (ZF), Minimum
Mean Square Error (MMSE) , Maximum Likelihood (ML), Vertical
Bell Laboratory Layered Space Time (V-BLAST), QR decomposition,
Least Square (LS), Maximum A Posteriori (MAP), channel estimation,
Alamouti coded OFDM.